The present invention relates to a method and apparatus for the storage of continuous lengths of rigid pipeline. The invention is most particularly intended for use in the temporary storage of lengths of rigid pipeline prior to said pipeline being spooled onto the storage reel of a reel-type marine pipelaying vessel.
In reel-pipelaying operations, the pipeline to be laid is spooled onto a reel, mounted on the pipelaying vessel, and subsequently unspooled as the pipe is laid. The pipe is plastically deformed during spooling, and is straightened during unspooling prior to departure from the vessel.
The reel pipe-laying vessel "Apache" has a pipelay reel with a capacity of approximately 2000 tonnes of rigid pipeline up to 16 inches diameter. The pipeline is assembled by welding standard 40 foot pipe joints into 1 kilometre stalks which are stored on racks at an onshore spoolbase. The stalks may be assembled and stored whilst the vessel is away from the spoolbase on pipelaying operations. When the vessel is at the spoolbase to receive a load of pipe, the pre-assembled stalks are spooled onto the reel of the vessel with tie-in welds between stalks being made during the spooling process. The need to make, inspect and coat the tie-in welds necessarily prolongs the nonproductive time required to spool a load of pipe onto the vessel. It would be desirable to reduce the length of time occupied by the spooling operation, so as to maximise the availability of the vessel for productive pipelaying operations.